改造对沸石基复合环境材料表面结构的影响及应用

Effects of modification on the surface structure and application of composite environmental materials based on zeolite

以天然斜发沸石为研究对象,采用不同改造方法对其进行改造,研究发现LaCl3化学改造2h,500℃高温下焙烧1h后所得沸石基复合环境材料去除污水中磷的性能有了较大提高。SEM和EDS测试材料的结果表明,天然沸石改造后其表面形貌发生了改变,孔结构得到了扩展,改造前后材料主要成分均为Si、Al、O,但改造后材料中La离子含量明显增加。材料表面结构测试分析发现,改造后复合材料孔道得到拓宽,孔径分布更为均匀,孔容积、比表面积、孔径数量和孔隙率与沸石原材料相比均有所增加。在此基础上,研究了沸石基复合环境材料用量、处理时间及废水pH值对材料除磷效果的影响,结果表明,材料在用量1.2g/L、处理时间3h、pH值3～7的条件下,对废水中磷去除率可达98.46%。

The modification of natural clinoptilolite by different methods was studied. It was shown that the zeolite which was modified by being soaked in hydrated lanthanum chloride for 2h and roasted at temperature 500 C for lh could effectively remove phosphate from wastewater. The results of SEM-EDS analysis show that pore structure was expanded to some extent and the shape of pores were obviously changed; the main components of zeolite before and after modification were all Si, Al and O, but the content of lanthanum ion increased in modi- fied zeolite. The results of surface texture analysis indicate that modified zeolite channel get broaden and pore size distribution was more even; the pore volume, specific surface area and porosity were increased. This may improve the adsorption performance of zeolite. Based on these, the effects of additive dosages, appropriate time and pH on the phosphate removal capacity of modified zeolite was studied. The results show that the appropri ate conditions are 1.2g/L of additive dosages, 3h of appropriate time and 3-7 of pH value. The phosphorus re moval rate was 98.46 % under the optimized conditions.